Multi-mode coordinator for medical device function

ABSTRACT

The invention is directed to an externally applied coordinator for communication and/or control of 2 or more implantable medical devices that may utilize different telemetry communication techniques. The coordinator receives telemetry signals from 2 or more implantable medical devices and provides functional direction to each of the devices to provide coordinated therapy and/or diagnostic function. The coordinator automatically configures itself for communication with a given medical device based either on the telemetry signal it receives or programmed by the physician. Specifically the coordinator is implemented as a software based, power efficient receiver/transmitter based upon an inexpensive, simple motor-controller DSP.

RELATED APPLICATIONS

This application is a continuation in part of Ser. No. 10/722,891, filedNov. 26, 2003.

FIELD OF THE INVENTION

The invention relates to implantable medical devices, particularly,medical devices equipped to communicate via transmitting and receivingtranscutaneously transmitted telemetry signals. More particularly, theinvention relates to a device and method for the coordination offunction between 2 or more implantable medical devices with or withoutsimilar telemetry systems. In particular, the inventive device isconstructed in a temporary tape-on form from an energy efficient,inexpensive, and simple motor controller DSP.

BACKGROUND OF THE INVENTION

Today, as the population ages, implantable medical devices (IMDs) are inuse for various cardiac, pulmonary and neurological diseases. In fact,many elderly patients often have multiple disease states that may behelped by several different IMDs. Additionally, several neuro-cardiologydiseases have several simultaneous physiologic manifestations. Forexample, epilepsy may often have concomitant cardiac and/or pulmonaryanomalies and Parkinson's Disease patients also often have cardiacarrhythmia manifestations. Often epilepsy or Parkinson's patients thathave been newly diagnosed or have transient periods when their currentmedicants are no longer effective and must be changed/modified (i.e.,drug type, dosage levels, timing, etc.), have transient episodes ofcardiac or pulmonary anomalies that may last a few days, a few weeks toseveral months in length.

Additionally, often when an IMD is required for implantation, anotherdevice may already be implanted in the patient (i.e., a neuro stimulatormay now be required for recently diagnosed epilepsy and a pacemaker orICD may already be present for cardiac anomalies such as bradycardia ortachyarrhythmia). With IMDs generally having a longevity of 5-8 yearsminimum, and many lasting 15 years, it would be cost effective for aphysician to make use of the remaining life of the previously implanteddevice and, in doing so, may improve the effectiveness of the therapydelivered to the patient, reduce the pain/discomfort of therapydelivered and/or improve diagnostics of the new device implanted. The 2IMD devices would have to have their operation and function synchronizedand coordinated to provide these benefits.

One issue with the integration of 2 or more IMDs in a patient is theadditional “overhead” of software required for system function,integration of function, intra-device communication, new algorithms fortherapies or diagnostics and the like. Most IMDs have little free RAM ordownloadable code space left in the device after implant to be able tofunction as the system integrator/coordinator.

Another issue with the synchronization of operation of 2 IMDs is thatthe telemetry method, modulation and/or coding format may be differentbetween, and complicating the communication between, the 2 devices.Additionally, as above, neither of the 2 IMDs would unlikely be able toprovide the code space and circuit capability to allow the modulation,demodulation, coding and decoding of telemetry formats to allow thisintra-device communication.

In this context, telemetry generally refers to communication of data,instructions, and the like between a medical device and a medical deviceprogrammer operated by a physician. For example, a programmer may usetelemetry to program a medical device to deliver a particular therapy toa patient. In addition, the programmer may use telemetry to interrogatethe medical device. In particular, the programmer may obtain diagnosticdata, event marker data, activity data and other data collected oridentified by the medical device. The data may be used to program themedical device for delivery of new or modified therapies. In thismanner, telemetry between a medical device and a programmer can be usedto improve or enhance medical device therapy.

Telemetry typically involves wireless data transfer between a medicaldevice and the programmer using radio frequency (RF) signals, infrared(IR) frequency signals, or other electromagnetic signals. Any of avariety of modulation techniques may be used to modulate data on arespective electromagnetic carrier wave. Alternatively, telemetry may beperformed using wired connections, sound waves, or even the patient'sflesh as the transmission medium. A number of different telemetrysystems and techniques have been developed to facilitate the transfer ofdata between a medical device and the associated programmer.

Many IMDs support telemetry. Examples of telemetry-capable IMDs includeimplantable cardiac pacemakers, implantable defibrillators, implantablepacemaker/cardioverter/defibrillators (ICDs), implantable muscularstimulation devices, implantable brain stimulators, other implantableorgan stimulation devices, implantable drug delivery devices,implantable cardiac monitors or loop recorders (ILRs), and the like.Telemetry, however, is not limited to communication with IMDs. Forexample, telemetry may allow an IMD to communicate with non-implantedmedical devices in substantially the same way as it is used withprogrammers. Examples include patient-carried monitors, patientactivators, remote monitoring systems and the like.

The evolution and advancement of IMD telemetry has yielded a number ofadvances in the art including, for example, improved communicationintegrity, improved data transmission rates, improved communicationsecurity, and the like. Moreover, as new therapeutic techniques aredeveloped, telemetry allows the new techniques to be programmed intoolder medical devices, including devices previously implanted in apatient. Unfortunately, the evolution of telemetry has also resulted inproliferation of a wide variety of different systems and communicationtechniques that generally require a unique programmer for communicationwith each type of device. Consequently, different types of medicaldevices, medical devices manufactured by different companies, or evensimilar medical devices manufactured by the same company, often employdifferent telemetry techniques. Accordingly, a wide variety of differentprogrammers are needed to communicate with different medical devices inaccordance with the different telemetry techniques employed by themedical devices.

A proposed solution to the large and diverse number of programmersrequired in a hospital and/or follow-up clinic environment to program,interrogate or follow patients with IMDs is a “universal programmer” asproposed, for example, by P Stirbys in “A Challenge: Development of aUniversal Programmer”, PACE, Vol 16, April 1993, pg 693-4 and by RFortney, et al. in “Activation Times for “Emergency Backup” Programs”,PACE, Vol 19, April 1996, pg 465-71. As pointed out in these articles,the difficulty of implementing multiple up/down link formats in a singleprogrammer is formidable.

Prior art programmers have included optimized and customized bandpassfilters and demodulators for demodulating and detecting the telemetereddata signal from an IMD from a particular manufacturer. It would beprohibitively expensive, large and complex to incorporate the requiredamplification, filtering and demodulation of all manufacturers' IMDs ina single programmer.

Additionally, the integration of the circuitry and firmware/softwareinto IMDs to allow intra-device communication and systemintegration/control would be unduly complex, bulky, power hungry andvery difficult from a mechanical packaging perspective. There is a needfor an energy efficient system integrator and coordinator apparatus thatis configurable to receive and demodulate data telemetered from avariety of implantable devices and communicate to another IMD providingintegrated/coordinated diagnostic function and/or therapy deliverable toa patient. The present invention fulfills this need.

SUMMARY OF THE INVENTION

In general, the invention is directed to a system coordinator for 2 ormore IMDs and the communication between those medical devices that mayutilize different telemetry communication techniques. The systemcoordinator receives telemetry signals from a given medical device, andselects an appropriate communication mode, which can be pre-programmedinto the coordinator as one of a plurality of possible communicationmodes. For example, upon receiving a telemetry signal from the medialdevice, the coordinator may identify a signature associated with thereceived telemetry signal. The coordinator can then select theappropriate communication mode, such as by accessing a lookup table thatassociates signatures with communication modes. Accordingly, thecoordinator can selectively configure itself for communication with agiven medical device based on the telemetry signal it receives from thatmedical device.

In one embodiment, the invention provides a method comprising receivinga first signal from a medical device, and selecting a communication modefrom a plurality of possible communication modes based on the firstsignal. For example, selecting the communication mode based on the firstsignal may include identifying a signature that substantially correlatesto the first signal, and selecting a communication mode associated withthe signature.

In another embodiment, the invention provides a system comprising afirst medial device, a second medial device, and a system coordinator.For example, the coordinator receives a first signal from the firstmedial device, selects a first communication mode from a plurality ofpossible communication modes based on the first signal, generates asecond signal that complies with the first communication mode, sends thesecond signal to the first medical device, receives a third signal fromthe second medial device, selects a second communication mode from theplurality of possible communication modes based on the third signal,generates a fourth signal that complies with the second communicationmode, and sends the fourth signal to the second medical device.

In yet another embodiment, the communication modes may be simplyprogrammed by the patient's physician based on the model numbers of theIMDs present.

The present invention provides various advances in the art. Inparticular, the invention can allow the extension of the useful lifetimeof an IMD and/or provide improved function, including diagnostics andtherapy, by allowing intra-device communication and system coordinationbetween 2 or more IMDs. A multi-mode system coordinator can be used tocommunicate and provide system integration and coordination on aselective basis between a plurality of different medical devices with,or without, differing telemetry communication modes.

The invention may also provide distinct advances in the art in terms ofthe size (form factor) and mechanical configuration of a coordinator,useful for improved patient therapy and/or diagnostics. For example, anumber of mechanical configurations are envisioned, including wearableconfigurations such as configurations similar to jewelry, a wristwatchor a belt buckle to be worn by the patient or medical personnel. Inaddition, a coordinator in the form of an ID card or adhesive patch witha removable memory card are envisioned for use by a patient so thatdiagnostic information can be collected on the removable memory cardwhen the patch is adhered to the patients skin. In that case, the memorycard may be removed from the coordinator and sent it to a physician foranalysis without the need to send the entire coordinator to thephysician. Accordingly, the coordinator can be reused with anothermemory card. Of course, the coordinator itself could also be sent by thepatient to the physician, in accordance with other embodiments. Theseand other unique wearable configurations can be realized in variousembodiments of the invention, some of which may have dimensions lessthan approximately 60 millimeters by 90 millimeters by 15 millimeters,i.e., a form factor similar to that of a thick credit card.

The techniques described herein may be implemented in a systemcoordinator in hardware, software, firmware, or any combination thereof.If implemented in software, invention may be directed to a computerreadable medium comprising program code, that when executed, performsone or more of the techniques described herein. Additional details ofvarious embodiments are set forth in the accompanying drawings and thedescription below. Other features, objects and advances in the art willbecome apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual diagram illustrating a multi-mode programmercommunicating with an exemplary medical device implanted in a humanbody.

FIG. 2 is a block diagram illustrating telemetry between a multi-modeprogrammer and a set of different medical devices.

FIG. 3 is a block diagram of a multi-mode programmer that supports aplurality of communication modes for communicating with differentmedical devices via different telemetry techniques.

FIG. 4 is a more detailed block diagram of a multi-mode programmer.

FIGS. 5 and 6 are diagrams illustrating an embodiment of a multi-modeprogrammer taking the form of an adhesive patch.

FIGS. 7 and 8 are flow diagrams illustrating techniques in accordancewith embodiments of the invention.

FIG. 9 is a diagram illustrating an alternative embodiment utilizing themulti-mode programmer of the invention.

FIG. 10 is a simplified schematic representation of the software basedmulti-mode programmer of the present invention.

FIG. 11 is a schematic diagram of the front-end receiver, transmittercoil interface and DSP portions of the multi-mode programmer accordingto an embodiment of the invention.

FIG. 12 is a diagram of the uplinked RF telemetry signal from animplanted medical device showing one embodiment of ping detection anddemodulation.

FIG. 13 is a diagram of an uplinked RF signal showing a zero crossingextrapolation according to an embodiment of the invention.

FIG. 14 is a diagram of an uplinked RF signal showing a power reductiontechnique utilizing a window sampling method.

FIG. 15 is a conceptual diagram illustrating a multi-mode coordinator ofthe present invention communicating with 2 exemplary medical devicesimplanted in a human body.

FIG. 16 is a diagram of a method of implementing the implanting of asecond IMD and initiating communication between the first and secondIMDs.

DETAILED DESCRIPTION

FIG. 1 is a conceptual diagram illustrating a multi-mode programmer 5communicating with an exemplary medical device 8 implanted in a humanbody 10. Medical device 8 represents one of a variety of medical devicesthat may communicate with programmer 5. Although illustrated as animplantable cardiac pacemaker, medical device 8 may take the form of avariety of other medical devices such as, for example, an implantabledefibrillator, an implantable pacemaker/cardioverter/defibrillator, animplantable muscular stimulus device, an implantable brain stimulator,an implantable nerve stimulator, an implantable drug delivery device,implantable monitor, or the like. In addition, medial device 8, asdescribed herein, is not necessarily limited to an implantable device.Also, in some cases, medical device 8 may correspond to a medical deviceused on non-human mammals or other animals. In short, the techniquesdescribed herein may be readily used with a wide variety of medicaldevices including implanted and non-implanted medical devices used todeliver therapy or perform diagnosis in humans, mammals, or other typesof living beings.

In the example shown in FIG. 1, medical device 8 includes a hermeticallysealed enclosure 14 that may include various elements, although theinvention is not limited to hermetically sealed devices. By way ofexample, enclosure 14 may house an electrochemical cell, e.g., a lithiumbattery, circuitry that controls device operations and records sensedevents, physiological activity and patient conditions, and a controlunit coupled to an antenna to transmit and receive information viawireless telemetry signals 12.

Programmer 5 communicates with medical device 8 via telemetry signals12. For example, programmer 5 may use telemetry signals 12 to programmedical device 8 to deliver a particular therapy to human body 10, suchas electrical stimulation, drug administration or the like. In addition,medical device 8 may use telemetry signals 12 to send information toprogrammer 5 such as diagnostic information, sensed conditionsassociated with the patient, information relating to therapy deliveredto the patient, or any other information collected or identified bymedical device 8. In this manner, telemetry allows communication betweenmedical device 8 and programmer 5.

In accordance with the invention, programmer 5 supports communicationvia a number of different telemetry modes. Accordingly, programmer 5 iscapable of receiving and interpreting telemetry signals sent by medicaldevices that use different types of telemetry. Moreover, programmer 5can communicate to different medical devices using selectedcommunication modes that correspond to the given medical device withwhich programmer 5 is currently communicating. The different telemetrymodes of programmer 5 may cause programmer 5 to select differenttelemetry techniques. For example, programmer 5 may be equipped todetect characteristic features of signals sent to programmer 5 viadifferent communication modes, such as unique carrier waveform shapes,amplitudes, frequency and/or timing of the modulated waveform, or thelike. Based on the detected characteristics, programmer 5 selects one ofthe telemetry modes appropriate for communication with medical device 8.

Programmer 5 may be embodied in a wide variety of mechanicalconfigurations. By way of example, programmer 5 may comprise a deviceworn on a patient's wrist, much like a wrist watch, and may evencomprise a fully functional wrist watch that tells time, but alsoincludes the programmer functionality described herein. Alternatively,programmer 5 may be worn around a patient's neck, like a necklace, oraround a patient's waist, like a belt. In other configurations,programmer 5 may be embodied in an identification card, a pendent, alaptop computer, a handheld computer, a pager, or the like. In somecases, programmer 5 may comprise a programmed computer used by emergencymedical personnel, e.g., in an ambulance, to communicate with a varietyof possible medical devices that may be implanted within a givenpatient. In still other cases, programmer 5 may be embodied as anadhesive patch that is adhered to a patient's skin. These and otherconfigurations of programmer 5 may be used in accordance with theinvention.

In any case, programmer 5 receives telemetry signals 12 from a givenmedical device 8, and dynamically selects an appropriate communicationmode, which can be pre-programmed into programmer 5 as one of aplurality of possible communication modes. For example, upon receiving atelemetry signal 12 from medical device 8, programmer 5 may identify asignature associated with the telemetry signal 12. Programmer 5 may thenselect the appropriate communication mode, such as by accessing a lookuptable (LUT) that associates signatures with communication modes. Then,the programmer 5 can configure itself for communication with medicaldevice 8 based on the telemetry signal 12 received from medical device8.

FIG. 2 is a block diagram illustrating telemetry between programmer 5and a set of different medical devices 8A-8D. Again, the differentmedical devices 8A-8D may comprise any of a wide variety of medicaldevices, including implanted and non-implanted medical devices, used todeliver therapy to humans, mammals, or even other types of livingbeings. In accordance with the invention, the different devices 8A-8Dcommunicate using different telemetry techniques. In other words, theformat of telemetry signal 12A is different from that of 12B, 12C and12D. For example, different telemetry signals 12 may have distinctcarrier waveforms defined by amplitude and frequency. Also, differenttelemetry signals 12 may be modulated differently, e.g., using amplitudemodulation (AM), frequency modulation (FM), pulse width modulation(PWM), pulse code modulation (PCM), pulse position modulation (PPM), orthe like. Also, different coding schemes may be associated withdifferent signals 12, such as phase-shift keying (PSK), orthogonalcoding, frame based coding, or the like. Programmer 5 may identify theseunique characteristics of the raw signal without performing ademodulation in order to identify the communication mode. An appropriatedemodulator can then be selected, as well as appropriate signaltransmission techniques and components.

Programmer 5 supports communication with the different devices 8A-8D bysupporting communication via each of the different telemetrycommunication modes associated with signals 12A-12D. In particular,programmer 5 selectively switches communication modes to match thecommunication mode of medical device 8, and thereby permit programming,interrogation or both. Programmer 5 may be configured to receive signalsin a frequency band known to correlate to all of telemetry signals 12,or may periodically tune to different frequency bands to tune forreception of different telemetry signals 12 over time.

The different medical devices 8A-8D may correspond to different types ofdevices, i.e., devices that deliver different types of therapy.Alternatively medical devices 8A-8D may comprise similar devicesmanufactured by different companies, which use different telemetrytechniques. In addition, medical devices 8A-8D may correspond to similardevices manufactured by the same company, but which use differenttelemetry techniques.

In most cases, medical devices 8A-8D correspond to different devicesimplanted or used on different patients. In some cases, however, medicaldevices 8A-8D may correspond to different devices implanted or used inone particular patient. In other words, a patient may have more than onemedical device 8 implanted within his or her body. In that case,programmer 5 may support communication with all of the different devicesimplanted and used within the same patient. In any case, the need fordistinct programmers for each device can be eliminated in favor of asingle multi-mode programmer 5 that supports a plurality ofcommunication modes.

FIG. 3 is an exemplary block diagram of a programmer 5 that supports aplurality of communication modes for communicating to different medicaldevices via different telemetry techniques. Programmer 5 is configuredto dynamically select different communication modes according to thecommunication modes presented from medical devices 8. As illustrated,programmer 5 may include an antenna 32, a control unit 34, a memory 36,and a power supply 38.

Antenna 32 may send and receive different electromagnetic telemetrysignals 12, such as radio frequency signals, as directed by control unit34. The invention, however, is not limited for use with electromagnetictelemetry signals, but may also used with other telemetry signals,including sound waves. In addition, in some embodiments, programmer 5may use the patient's flesh as a transmission line for communication ofelectromagnetic signals between medical devices and programmer 5.

In any case, programmer 5 supports communication according to aplurality of telemetry modes. In operation, control unit 34 ofprogrammer 5 receives telemetry signals via antenna 32. Antenna 32 maybe tuned to a large frequency band that covers any possible telemetrysignal that may be received from a device supported by programmer 5, ormay be periodically tuned by control unit 34 to individual frequenciesthat correspond to specific telemetry signals that are supported. In anycase, once a signal is received, control unit 34 conditions receivedsignals so that signatures associated with the received signals can beidentified. For example, control unit 34 may perform amplification orattenuation on received signals, and may also implement a phase lockedloop to properly synchronize the phase of a received signal with thesignatures to which the received signal is being compared.

The signatures may correspond to templates of expected waveforms thatcorrespond to possible telemetry signals that could be received. Thesignatures may include distinctive waveform characteristics indicativeof the respective telemetry signal, such as a particular frequency,amplitude, shape, modulation characteristic, or the like. Memory 36stores the signatures for every telemetry technique that is supported byprogrammer 5. Accordingly, control unit 34 compares received signalswith stored signatures by accessing memory 36. Then, after identifyingan acceptable match between a stored signature and a received telemetrysignal, e.g., 12A, programmer 5 is able to identify the telemetrytechnique associated with the medical device that sent signal 12A. Inother words, the received signals can be compared to signatures, and thesignatures can be mapped to communication modes.

Memory 36 may also store configuration parameters associated withdifferent communication modes for control unit 34. In addition, memory36 may include a lookup table (LUT) that maps signatures tocommunication modes, i.e., by mapping a number associated with asignature to a number associated with an associated communication mode.Thus, upon identifying a signature associated with a received telemetrysignal 12A, control unit can access the LUT in memory 36 to select theproper communication mode. Then, control unit 34 can be configuredaccording to the selected communication mode to output telemetry signalsthat the medical device associated with the received telemetry signal12A can understand. In addition, control unit 34 can configure itself sothat signals sent from the respective device can be properly demodulatedand interpreted. In short, the different communication modes supportedby programmer 5 can be programmed into memory 36, and then applied on aselective basis based on received telemetry signals 12.

FIG. 4 is a more detailed exemplary block diagram of programmer 5. Asillustrated, programmer 5 includes a power supply 38, such as a battery,that powers control unit 34 and memory 36. Antenna 32 is coupled tocontrol unit 34 to facilitate the reception and transmission of wirelesselectromagnetic telemetry signals. The invention, however, is notnecessarily limited for use with wireless signals or electromagneticsignals. Again, similar principles can be applied in a programmer thatcan be wired to one or more medical devices, or a programmer that usesthe patient's flesh or sound waves as the transmission medium fortelemetric communication.

Control unit 34 may include a programmable digital signal processor(DSP) 42 coupled to a crystal oscillator (not shown). Examples ofsuitable DSPs include the TI-TMS320C2000 family of DSPs; such as themodel number TI-TMS320LC2406 DSP, commercially available from TexasInstruments Incorporated of Dallas Tex., USA. By way of example, theoscillator may comprise a 5 MHz crystal, although other oscillatorscould be used. The TI-TMS320LC2406 DSP is a 16-bit fixed point DSPoriginally designed for motor control applications. The TI-TMS320LC2406DSP includes internal flash memory and a 10-bit analog to digitalconverter (ADC). Other DSPs and programmable microprocessors, however,could alternatively be used.

Memory 36 may comprise a removable memory card that couples to DSP 42via a memory connector, although non-removable memory could also beused. Removable memory cards can provide an added benefit in that thecard can be removed from programmer 5 and sent to a physician foranalysis. For example, after programmer 5 telemetrically communicateswith a given medical device 8, data from that medical device may bestored in memory 36. The data stored in memory 36 may be data selectedby programmer 5. In some cases, the data stored in memory 36 may beoverflow data from an internal memory associated with medical device 8,allowing programmer 5 to provide more continuous and more prolongedpatient monitoring capabilities. If memory 36 comprises a removablecard, the card may be removed from programmer 5 and sent to a physician,and a new card may be inserted in its place. In this manner, data from amedical device 8 can be easily provided to a physician, e.g., tofacilitate early diagnosis of problems.

Moreover, the use of memory cards can avoid the need to send the wholeprogrammer 5 to the physician. In addition, a more continuous and largersample of data from the medial device may be captured by sequentiallyinserting a number of memory cards into programmer 5 over a period oftime in which information is being sent from the respective medicaldevice. As one example, memory 36 may comprise a 64 or 256 Megabytemultimedia memory module commercially available by SanDisk of Sunnyvale,Calif., USA. Other removable or non-removable memory, however, may alsobe used.

Another advances in the art of removable memory cards and a DSP relatesto updating the function of the programmer 5. For example, in order toupdate programmer 5 to support new or different forms of telemetriccommunication, a different memory card, storing software to support thenew or different telemetry may be provided. In other words, a DSPconfiguration with removable memory provides advances in the art interms of scalability of programmer 5. If new or different telemetry isdeveloped, software can be likewise devolved and provided to programmervia a new removable memory card. Accordingly, in that case, the need todevelop a different programmer may be avoided. Instead, new algorithmscan be provided to programmer 5 via a new memory card that stores newinstructions that can be executed by the DSP.

Antenna 32 may comprise any of a wide variety of antenna configurations.In one particular example, antenna 32 may comprise a substantially flat,co-planer dual opposing coil antenna. For example, two opposing coilsmay be formed on a common substrate to provide two signal inputs tocontrol unit 34. The input of two or more signals to control unit 34 maysimplify signal processing within control unit 34, such as bysimplifying filtering. In addition, an antenna scheme utilizing multipleconcentric and co-planar antenna coils on a substrate may also reducethe form factor of programmer 5, which can facilitate wearableembodiments. The use of concentric and co-planar antenna coils may alsoimprove the reception of telemetry signals in a noisy environment.

Power supply 38 may comprise any of a wide variety of batteries or otherpower sources. For example, power supply 38 may comprise a rechargeableor non-rechargeable battery, such as a polymer or foil battery, alithium ion batter, a nickel cadmium battery, or the like. The batterymay have a voltage range of approximately 4.2 to 3.0 volts throughoutits useful service life and a capacity of 1.5 Ah, although the inventionis not limited in that respect.

In addition to DSP 42, control unit 34 of programmer 5 may include areceiver module 46 and a transmitter module 48. Receiver module 46 andtransmitter module 48 may be integrated or may comprise separatecircuits. The composition of receiver module 46 and transmitter module48 may depend on the particular DSP 42 used in control unit 34 as wellas the particular communication modes supported by programmer 5.

In general, receiver module 46 conditions a received telemetry signalfor analysis by DSP 42. Receiver module 46 may include ananalog-to-digital converter (ADC), although some DSPs, such as theTI-TMS320LC2406 mentioned above, include an ADC as part of the DSP.Receiver module 46 may also include one or more amplifiers, a variablegain amplifier (VGA), one or more filters, automatic gain control (AGC),if needed, and a phase-locked loop for synchronizing a received signalso that an in-phase sample can be identified. These and/or othercomponents of receiver module 46 condition a received telemetry signalas required by DSP 42 so that signal analysis can be performed. In somecases, DSP 42 may configure both itself and receiver module 46 forreception of a given telemetry signal that is expected, such as byselectively switching on a subset of the bandpass filters in DSP 42 andcontrolling the gain of a received signal in receiver module 46.

Transmitter module 48 conditions output signals for wirelesstransmission to a medical device via antenna 38. For example, DSP 42 maygenerate timed output signals based on a selected communication mode inorder to communicate with the respective medical device 8 via telemetry.Transmitter module 48 can receive signals from DSP 42 and amplify thesignals for transmission via antenna 38. For example, transmitter module48 may include transmit circuitry for driving antenna 38, such as a setof field effect transistors (FET) that output relatively large outputvoltage pulses in response to relatively small input voltages receivedfrom DSP 42. Transmitter module 48 may also include various otherfilters, amplifiers, or the like, that may be selectively activatedbased on the given communication mode. For example, in some cases, aselected communication mode identified by DSP 42 can cause DSP 42 tosend control signals to transmitter module 48 to configure transmittermodule 48 for telemetric communication consistent with the selectedcommunication mode. In any case, transmitter module 48 conditions outputsignals from DSP 42 for wireless telemetric transmission to a medicaldevice.

DSP 42 of programmer 5 may include several different bandpass filtersand several different demodulators, such as one or more amplitudedemodulators, one or more frequency-shift keyed (FSK) demodulators, oneor more phase-shift keyed (PSK) demodulators, and the like. For example,these different components may be programmed as software or firmware. Inany case, DSP 42 selects the particular bandpass filter(s) anddemodulator type to process the digitized signal according to thecommunication mode that is selected. In other words, DSP compares theraw signal that is received to signatures in order to identify theappropriate communication mode, and then selectively enables theappropriate demodulator so that subsequent signals can be demodulatedand interpreted.

An additional function implemented by DSP 42 may include the control ofa variable-gain amplifier (VGA) or other components included in receivermodule 46 or transmitter module 48. For example, this may further ensurethat the receiver module 46 supplies to the A/D converter of DSP 42 asignal having a desired peak amplitude. Moreover, VGA control in the DSP42 may provide flexibility in software so that adjustments can be madeto properly condition a wide variety of telemetry signals.

In order to facilitate the automatic gain control (AGC) between DSP 42and receiver module 46, receiver module 46 may include adigital-to-analog (D/A) converter to convert a digital control wordsupplied from DSP 42 to a corresponding analog voltage level forvariable-gain amplification.

One specific configuration of programmer 5 may be formed of theexemplary components listed above including the TI-TMS320LC2406 DSP,SanDisk memory module, a dual coil planer antenna, a sufficiently smallbattery, and individual hardware components to implement the receivermodule 46 and transmitter module 48. In that case, programmer 5 mayrealize a compact form factor suitable for inconspicuous use by apatient, e.g., to collect information from a medical device and send thememory cards to the physician. A minimal amount of communication fromprogrammer 5 to the medical device may prompt the medical device touplink the requested information. For example, such exemplary componentsmay be used to realize a programmer 5 having dimensions less thanapproximately 60 millimeters by 90 millimeters by 15 millimeters. Inother words, programmer 5 can be made to dimensions correspondingroughly to the size of a thick credit card. Such reduced size can beparticularly useful for wearable embodiments of programmer 5.

If desired, programmer 5 may also include an activation switch (notshown), to allow a patient to initiate communication with a medicaldevice. For example, if the patient identifies pain or other problems,it may be desirable to initiate communication, e.g., to cause themedical device to communicate sensed information to programmer 5. Inthat case, an activation switch can provide the patient with the abilityto ensure that sensed conditions are stored in programmer 5 duringperiods of time when physical problems may be occurring to the patient.

Moreover, programmer 5 may include other user interface features, suchas a display screen, a speaker, or a blinking light. For example,feedback in the form of sound or light flashes, images, instructions, orthe like may be useful to a patient, e.g., to indicate thatcommunication has been initiated or to indicate to the patient that theprogrammer is positioned correctly for such communication.

FIGS. 5 and 6 are diagrams illustrating one embodiment of programmer 5in the form of an adhesive patch. In that case, programmer 5 may includean adhesive strip 51 for attaching programmer 5 to a patient's skin. Inaddition, electrodes 55 may also be used to facilitate the reception ofsignals though the patients flesh, although the use of electrodes wouldnot be necessary for every embodiment. In other words electrodes 55 mayprovide an alternative to antenna 52 for the transmission and receptionof signals. Accordingly, both electrodes 55 and antenna 52 may beelectrically coupled to control unit 34.

Programmer 5 (in this case a patch) is configured to dynamically selectdifferent communication modes according to the communication modespresented from medical devices 8. As illustrated, programmer 5 mayinclude an antenna 52, a control unit 34, a memory 36, and a powersupply 38, an adhesive strip 51, a protective sheath 53 and electrodes55.

Antenna 52 may comprise a coplanar dual coil antenna that sends andreceives electromagnetic telemetry signals as directed by control unit34. Alternatively or additionally, electrodes 55 may be used to send andreceive the signals. The protective sheath 53 may substantiallyencapsulate one or more of the components of programmer 5.

As outlined above, programmer 5 (in this case a patch) supportscommunication according to a plurality of telemetry modes. Control unit34 compares received signals with stored signatures by accessing memory36. Then, after identifying an acceptable match between a storedsignature and a received telemetry signal, programmer 5 is able toidentify the telemetry technique associated with the medical device thatsent the signal.

Memory 36 stores the signatures and may also store configurationparameters associated with different communication modes for controlunit 34. In addition, memory 36 may include a lookup table (LUT) thatmaps signatures to communication modes, i.e., by mapping a numberassociated with a signature to a number associated with an associatedcommunication mode. Thus, upon identifying a signature associated with areceived telemetry signal, control unit 34 can access the LUT in memory36 to select the proper communication mode. Then, control unit 34 can beconfigured according to the selected communication mode to outputtelemetry signals that the medical device associated with the receivedtelemetry signal can understand. In addition, control unit 34 canconfigure itself so that signals sent from the respective device can beproperly demodulated and interpreted.

As mentioned above, memory 36 may comprise a removable memory card.Accordingly, memory 36 may be removed from programmer 5, such as via aslot or hole formed in sheath 53. Alternatively, sheath 53 may be pulledback to expose memory 36, allowing memory 36 to be removed or replacedand possibly sent to a physician for analysis.

In still other embodiments, programmer 5 may be embodied in a wristwatch, a belt, a necklace, a pendent, a piece of jewelry, an adhesivepatch, a pager, a key fob, an identification (ID) card, a laptopcomputer, a hand-held computer, or other mechanical configurations. Aprogrammer 5 having dimensions less than approximately 60 millimeters by90 millimeters by 15 millimeters can be particularly useful for wearableembodiments. In particular, a configuration similar that thatillustrated in FIGS. 5 and 6 using the exemplary components listedherein may be used to realize a programmer with a small enough formfactor to facilitate different wearable embodiments. Additionalcomponents may also be added, such as a magnet or electromagnet used toinitiate telemetry for some devices.

FIG. 7 is a flow diagram illustrating a technique consistent with theprinciples of the invention. As shown, programmer 5 receives a telemetrysignal 12 from a medical device 8 (71). Control unit 24 of programmer 5selects a communication mode based on the received signal (72).Programmer 5 then communicates with medial device 8 using the selectedcommunication mode (73).

In order to select the proper communication mode based on the receivedsignal (72), control unit 24 of programmer 5 may identify a signatureassociated with the received signal. More specifically, receiver module46 conditions a received telemetry signal so that it falls within thedynamic range of DSP 42. DSP 42 samples the conditioned signal andcompares the digital sample to various signatures stored in memory 36.For example, DSP 42 may perform a correlation operation to compare adigital sample of a received signal to various signatures stored inmemory 36. In particular, the correlation operation may compare thefrequencies, phase shifts, pulse widths, or any other variable betweenthe digital samples of the received signal to those of the differentsignatures. Upon identifying a signature that matches the digital sampleof the received signal to within an acceptable degree (which may also beprogrammable), DSP 42 can configure programmer 5 according to acommunication mode associated with the signature. In other words, oncethe appropriate signature has been identified, DSP 42 can select acommunication mode, such as by accessing a LUT in memory 36 that mapssignatures to communication modes.

Upon identifying the necessary communication mode for telemetriccommunication with a respective medical device 8, control unit 34configures for such communication. For example, DSP 42 may select anappropriate set of bandpass filters and an appropriate demodulator, eachof which may be software implemented as part of DSP 42. In addition, insome cases, DSP 42 may send control signals to receiver module 46 andtransmitter module 48 to configure those modules 46, 48 for respectivereception and transmission consistent with the selected communicationmode. In this manner, programmer 5 can be configured for communicationaccording to a first telemetric mode of communication, and thenreconfigured for communication according to a second (different)telemetric mode of communication. In some cases, a large number ofdifferent communication modes can be supported by programmer 5.

FIG. 8 is another flow diagram illustrating a technique consistent withthe principles of the invention. As shown, programmer 5 initiatestelemetry with a medical device 8 (81). In most cases, in order topreserve battery life in a medical device, the medical device does notsend telemetry signals unless it receives a request for such signals.Accordingly, programmer 5 can be configured to initiate telemetry withmedical devices (81) by sending an appropriate request. Moreover, sincethe initiation required to cause a given medical device to send atelemetry signal may differ with the device, programmer may perform aplurality of initiation techniques so as to cause any device supportedby programmer 5 to send a telemetry signal.

For some devices, a magnetic field may be used to initiate telemetry,such as by magnetically activating a switch on the respective device tocause the device to send telemetry signals. Accordingly, programmer 5may include a magnet or an electromagnet that generates the requiredmagnetic field to cause the medical device to send a telemetry signal.For other devices, telemetry from a medical device 8 may begin uponreceiving a particular wireless signal that corresponds to a request fortelemetry. Accordingly, control unit 24 of programmer 5 may beconfigured to send one or more different request signals to provoke aresponse from the medical device. In some cases, control unit 24 maysend different request signals over time to provoke responses fromdifferent medical devices for which programmer 5 supports telemetry.Thus, if a particular device is in proximity to programmer 5, eventuallythe appropriate request signal will be sent from programmer 5 to thatdevice.

In any case, once programmer 5 has initiated telemetry with the medicaldevice (81) causing the medical device to send a telemetry signal,programmer 5 receives the signal from the medical device (82). Controlunit 24 of programmer 5 identifies a signature stored in memory 26 thatcorrelates with the received signal (83). More specifically, DSP 42generates a digital sample based on a signal conditioned by receivermodule 46, and compares the digital sample to the signatures stored inmemory by invoking a correlation operation.

Upon identifying a signature stored in memory 26 that correlates withthe received signal (83), control unit 24 identifies a medical deviceassociated with the signature (84). More specifically, DSP 42 accesses aLUT in memory 26 which maps signatures to communication modes, andselects from the LUT, the communication mode associated with theidentified signature.

Control unit 24 then configures programmer 5 for communication with themedical device 5 according to the selected communication mode (85). Morespecifically, DSP 42 selects particular bandpass filter(s) and ademodulator to process received telemetry signals in accordance with thecommunication mode that is selected. In addition, DSP 42 may sendcontrol signals to one or more components included in receiver module 46or transmitter module 48 to configure the modules to condition receivedsignals and to condition output signals according to the communicationmode that is selected.

Programmer 5 can then telemetrically communicate with the medical device(86). This telemetric communication may be used for any of a widevariety of desirable communication that can occur between a programmerand a medical device. For example, programmer 5 may telemetricallycommunicate with the medical device to program a new therapy techniqueinto the medical device. In particular, device 5 may be configured toreceive input from a physician or medical personnel specifying a therapyto be performed, and may send a signal to the medical device accordingto the selected communication mode to direct the medical device toperform the therapy.

Alternatively, programmer 5 may telemetrically communicate with themedical device 8 to request stored information corresponding, forexample, to diagnostic information, sensed conditions associated withthe patient, information relating to therapy delivered to the patient,or any other information collected or identified by the medical device.In that case, programmer 5 may receive the requested information fromthe medical device in response to the request for stored informationsent according to the appropriately selected communication mode. Theseor other communications may occur between a medical device andprogrammer 8 once programmer has identified the appropriatecommunication mode, and configured according to that communication modeconsistent with the principles of the invention.

FIG. 9 is a conceptual diagram illustrating an alternative embodimentutilizing the multi-mode programmer 5 of the present inventioncommunicating with an exemplary medical device 8 implanted in a humanbody 10 and, additionally, communicating to an external remote monitorthat may be connected to a network (in a hospital or clinic) or to theInternet for long distance remote monitoring. This embodimentillustrates a system that allows the retrofitting of the existingimplant base of near field telemetry pacemakers and defibrillators(totaling several million devices implanted worldwide) to be simply,inexpensively and with no patient trauma updated to a far fieldtelemetry system to allow the remote monitoring of this group ofpatients. Implantable medical device 8 represents one of a variety ofmedical devices that may communicate with programmer 5. Althoughillustrated as an implantable cardiac pacemaker, medical device 8 maytake the form of a variety of other medical devices such as, forexample, an implantable defibrillator, an implantablepacemaker/cardioverter/defibrillator, an implantable muscular stimulusdevice, an implantable brain stimulator, an implantable nervestimulator, an implantable drug delivery device, implantable monitor, orthe like. Multi-mode programmer 5 may take the form of a belt worn pagerlike device, a pendant worn around the patient's neck, a wrist wornwatch like device, a tape-on patch-like device or any other form factorthat allows improved patient comfort and safety for long termmonitoring.

In the example shown in FIG. 9, medical device 8 includes a hermeticallysealed enclosure 14 that may include various elements, although theinvention is not limited to hermetically sealed devices. By way ofexample, enclosure 14 may house an electrochemical cell, e.g., a lithiumbattery, circuitry that controls device operations and records sensedevents, physiological activity and patient conditions, and a controlunit coupled to an antenna to transmit and receive information viawireless telemetry signals 12.

Programmer 5 communicates with medical device 8 via near field telemetrysignals 12—as substantially described in U.S. Pat. No. 4,556,063 toThompson, et al. and U.S. Pat. No. 5,127,404 to Wyborny, et al. andincorporated herein by reference in their entireties. For example,programmer 5 may use telemetry signals 12 to program medical device 8 todeliver a particular therapy to human body 10, such as electricalstimulation, drug administration or the like. In addition, medicaldevice 8 may use telemetry signals 12 to send information to programmer5 such as diagnostic information, sensed conditions associated with thepatient, information relating to therapy delivered to the patient, orany other information collected or identified by medical device 8. Inthis manner, telemetry allows communication between medical device 8 andprogrammer 5. Additionally programmer 5 communicates to the remotemonitor device 7 via far field telemetry signals 3—as substantiallydescribed in U.S. Pat. No. 5,683,432 to Goedeke, et al. and incorporatedherein by reference in its entirety. For example, the system describedin association with FIG. 9 may allow remote monitoring of high-risk CHFor arrhythmia patients as substantially described in U.S. Pat. No.5,752,976 “World Wide Patient Location and Data Telemetry System forImplantable Medical devices” to Duffin et al. and incorporated herein byreference in its entirety.

FIG. 10 is a simplified schematic representation of a software basedmulti-mode transmitter/receiver/programmer of the present invention. Thedesign of programmer 5 consists of a single chip digital signalprocessor (DSP) 100. Examples of suitable DSPs include theTI-TMS320C2000 family of DSPs; such as the model number TI-TMS320LC2406DSP, commercially available from Texas Instruments Incorporated ofDallas Tex., USA. By way of example, the oscillator 118 may comprise a40 MHz crystal, although other oscillators could be used. TheTI-TMS320LC2406 DSP is a 16-bit fixed point DSP, low cost ($3), fullystatic with low power modes originally designed for motor controlapplications. The TI-TMS320LC2406 DSP includes internal flash memory anda 16 channel 10-bit analog to digital converter (ADC) with 2Ms/scapability. Other DSPs and programmable microprocessors, however, couldalternatively be used.

Continuing, FIG. 10 shows the unique antenna scheme within theprogrammer head as substantially described in U.S. Pat. No. 6,298,271“Medical System Having Improved Telemetry” to Weijand incorporatedherein by reference in its entirety. The antenna scheme utilizes a firstantenna 102 and a second antenna 104, the antennas disposed in aconcentric and co-planar manner. The smaller area antenna 104 (in thisexemplary case the area of antenna 104 is ¼ the size of antenna 102)contains 4 times the number of turns of the larger antenna 102. Thisconcentric and co-planar disposition permits the cancellation of farfield signals (i.e., noise) and the reception of near field differentialsignals. It also permits the multi-mode programmer or peripheral memorypatch to be of much smaller and, thus, a more portable size than waspreviously possible. Additionally, the antenna design results in asignificant reduction in circuit design complexity. Low noise, wide bandamplifiers 106, 108, 110 and 112 amplify the received antenna signalsand input them to the DSP 100 ADC inputs for sampling. Downlink drivers114 and 116 under control of DSP 100 provide downlink telemetry to animplanted medical device 8 (FIG. 1). Optionally, the SPI bus interface122 and removable memory 120 may be added for a peripheral memoryembodiment.

FIG. 11 is a schematic diagram of the front-end receiver, transmittercoil interface and DSP portions of the multi-mode programmer 5 accordingto an embodiment of the invention. The antenna system consists of 2coils—an outer, larger coil 102 and an inner, smaller coil 104. Innercoil 104 has a larger number of turns than outer coil 102 to match theinductance of the 2 coils. The difference signal from the 2 coils allowa near field telemetry signal to be received while rejecting far fieldnoise signals as described in U.S. Pat. No. 6,298,271 to Weijand andincorporated herein by reference in its entirety. Fixed gain amplifiers106, 108, 110 and 112 amplify the received signal and provide 4 analogsignal channels to the DSP ADC inputs (described below). Capacitors 113and 115 and driver switches 114 and 116 control the downlinktransmission to an implantable medical device 8. Independent control ofthe switches 114 and 116 by the DSP 100 allow non-overlap switchcontrol. The circuit of FIG. 11 is powered by a battery and may includean optional voltage regulator (both not shown).

The DSP 100 contains 16-channel, 10 bit analog to digital converter(ADC) with independent ADC controller that samples and digitizes the 4analog signals from amplifiers 106, 108, 110 and 112. The MAC processorunder control of instructions contained in embedded memory in the DSP100 processes, filters and demodulates the data samples received fromthe antenna system 102/104 from any of a large variety of conventionalimplantable devices. For ease of understanding, reference is made to theblock diagram of FIG. 12, which depicts these software functions inequivalent hardware blocks.

FIG. 12 is a diagram of the uplinked RF telemetry signal from animplanted medical device showing one embodiment of ping detection anddemodulation. The received and amplified signals are selected bymultiplexer 152 and inputted to ADC 154 where they are converted at arate of 700 kHz; the signal path is split into separate processing forodd and even samples. The odd 156 and even 158 correlators correlate thesignal with an exponentially decaying sinusoid similar to the uplinkpulse as described in the aforementioned '063 patent. As the correlatorcoefficients are zero every other sample (175 Khz signal sampled at 700kHz) the odd and even correlators are just half the size of the fullcorrelator. The results are absolute valued and summed 160 before beingdownsampled at 87.5 kHz (162) and filtered in FIR filter 164. Furtherprocessing detects peak and zero crossings 166 and frame and datadecoding 168.

FIG. 13 is a diagram of an uplinked RF signal 200 showing a zerocrossing extrapolation (FIG. 12 processing block 166) according to anembodiment of the invention. ADC samples are shown at 202, 204, 206, 208and 210. Ground potential or zero signal value is denoted at 212. Theextrapolated time of the zero crossing may be determined by the value(AD/AC)* time in uSec from sample 206 to 208. This extrapolation allowsa reduced ADC sample rate and thus a reduced battery power drain.

Additional power reduction concepts may be utilized individually or intandem. Specifically, the TI DSP has reduced power states that may beenabled during circuit inactivity. Additionally, the timing of many IMDuplink telemetry systems are crystal controlled allowing the system ofFIG. 11 to be powered down into a sleep mode and awakened during awindow of expected or possible uplink signal transmission. FIG. 14 showsan uplinked RF damped sinusoid 230 from a typical pulse positionmodulation system from an IMD. The DSP of FIG. 11 powers down afterpulse reception and awakens, opening a window 234 of a discrete length,enabling the ADC to begin sampling the signal 232 received by theantenna. After the detection of 2 cycles of the pinged signal (at 236)the ADC conversion is disabled, conserving power. Lastly, the properselection of the system clock allows the slowing down of the clock whenlow speed processing is required.

A further additional embodiment of multimode programmer system 5 asshown in FIGS. 5 and 6 above would include the use of the telemetryantenna 32 and DSP 42 to allow the recharging of a rechargeable battery38 in a battery powered system. The full control of the coil switches(114 and 116 of FIG. 11A) allows the software to control batteryrecharging. The charging is accomplished by using the telemetry coil toreceive a magnetic field at the frequency of the tuned antenna 102. Thesoftware detects the system basic frequency and adjusts the timer todrive the switches for synchronous rectification. The DSP's ADC is usedfor battery voltage monitoring and charge control.

The motor controller DSP based programmer of the present invention caneliminate the need for multiple programmers for telemetric communicationwith different medical devices. A multi-mode programmer of the presentinvention can be used to communicate with a plurality of differentmedical devices on a selective basis providing a universal programmer tominimize the programmers required to interrogate and program implantabledevices from several manufacturers.

In addition, the invention may find useful application as aninterrogator in emergency (first responder and emergency room) scenariosby facilitating the ability to identify and communicate with medicaldevices used by a given patient. In that case, the ability to obtaindiagnostic and therapeutic information from a given medical devicewithout requiring knowledge of the make and model of the device may savevaluable time, possibly saving lives. In this embodiment, theprogramming of all parameters may not be available but universal safetymodes may be programmed (such as emergency VVI). The interrogator of thepresent invention would downlink a command to the implanted device tocause an uplink telemetry transmission that would include themanufacturer, device model number, serial number, device status,diagnostic data, programmable parameters and contact information, ifpresent.

The device of the present invention coordinates the function andoperation of 2 or more implanted medical devices from the followinglist; pacemaker, implantable cardioverter/defibrillator (ICD), drugpump, neuro stimulator, drug pump or insertable loop recorder (ILR).

Specifically, the co-coordinator of the present invention may coordinateand/or synchronize the therapy of a pacemaker and ICD (providingimproved detection, threshold reduction and/or improved efficacy), a ICDand drug pump (pain suppression prior to, or during, therapy deliveryand/or threshold reduction), ICD and neuro stimulator (initiate painsuppression prior to, or during high voltage therapy delivery),pacemaker and ILR (improved detection utilizing both sense detectors),ICD and ILR (improved detection utilizing both sense detectors), andremote sensor to IMD including pacemaker, ICD, ILR, neuro stimulator ordrug pump to aid in detection. The synchronization of the 2 or moredevices may also provide protection for a non therapy-delivering device,preventing damage during high voltage stimulation.

The coordinator is preferably constructed as a transcutaneously appliedsimple, disposable, inexpensive patch implementation as substantiallydescribed herein above with respect to the apparatus and methods ofFIGS. 4-14.

The coordinator may be used on a patient who already has an implantedmedical device such as a pacemaker (i.e., rate responsive, singlechamber, dual chamber, 3 chamber cardiac resynchronization, or thelike), defibrillator (i.e., ventricular, atrial, with cardiacresynchronization, or the like), cardiac monitor (i.e., ILR), drug pumpor neuro stimulator. If the patient's disease state progresses ordeteriorates, the clinician often wants to upgrade the therapy device toadd additional capabilities. Often the need for a second therapy devicemay only be temporary such as for a few weeks or months. As an example,cardiac patients may progress to epileptic seizures that ultimately arecontrollable by drugs/medicants. Alternatively, epilepsy oftenprogresses to cardiac anomalies that may require temporary cardiactherapies such as an ILR or defibrillator. In these patients the needfor temporary expanded system is required for several days, weeks ormonths to allow the physician to titrate the appropriate drug regime forcontrol of the cardiac or neural anomaly. To date, the only way toupgrade therapy is to replace the implanted device with a device ofincreased capabilities.

The physician may choose to retain the existing IMD, add a secondimplanted device and the inventive device to coordinate the function ofthe 2 IMD systems. Upon the implant of a second device, the physicianattaches the coordinator patch and programs the 3 devices withprogrammer 5. The coordinator patch utilizes a telemetry link betweenitself and the 2 IMDs to allow the sensing of cardiac events, determinesthe appropriate therapy to be delivered and, again via the telemetrylinks, cause a course of therapy to be delivered by the appropriate IMDor, alternatively, by both IMDs. The telemetry links may consist ofsimilar frequencies and modulation types or, alternatively, may beentirely different telemetry formats as described herein above.

FIG. 15 is a simplified schematic view of the present invention showingan IMD 14 implanted in a patient 10. IMD 14 may be a pacemaker or ICDconnected to the patient's heart 20 via endocardial or epicardial leads22 (representative right ventricular (RV) and coronary sinus (CS) leadsshown in FIG. 15). Additionally, a neuro stimulator 16 is also implantedin patient 10. A brain stimulation lead 24 is shown connected tostimulator 16. Alternatively, a vagal nerve stimulation lead 26 is shownin FIG. 15. In yet another alternative embodiment IMD 16 may be a drugpump for delivery of a medicant through a catheter (not shown in FIG.15) to the brain, spinal cord or another organ.

A multi-mode programmer 12 is shown which may be used to program IMD 14and/or neuro stimulator/drug pump 16 via a 2-way wireless telemetrycommunication link 28. Additionally, stored diagnostic data may beuplinked and evaluated by the patient's physician utilizing programmer12 via 2-way telemetry link 28. The wireless communication link 28 mayconsist of an RF link (such as described in U.S. Pat. No. 5,683,432“Adaptive Performance-Optimizing Communication System for Communicatingwith an Implantable Medical Device” to Goedeke, et al. and incorporatedherein by reference in its entirety). A coordinator 18 is shown attachedto the patient's 10 chest and allowing 2-way communication to IMD 14 andneuro stimulator 16 via 2-way communication link 30. The wirelesscommunication link 30 may consist of an RF link (such as described inthe above referenced Goedeke '432 patent), an electromagnetic/ionictransmission (such as described in U.S. Pat. No. 4,987,897 “Body BusMedical Device Communication System” to Funke and incorporated herein byreference in its entirety) or acoustic transmission (such as describedin U.S. Pat. No. 5,113,859 “Acoustic Body Bus Medical DeviceCommunication System” to Funke and also incorporated herein by referencein its entirety). An external patient activator (not shown in FIG. 15)may optionally allow the patient 10, or other care provider (also notshown in FIG. 15), to manually activate the recording of diagnostic dataor activate therapy delivery.

In operation, the system of FIG. 15 monitors cardiac signals andfunction via cardiac contacting leads 22 and IMD 14 and brain signalsvia brain lead 24 and neuro stimulator 16. The coordinator 18 receivesthe sensing of cardiac or brain signals via telemetry 30 from IMD 14 andstimulator 16. Coordinator 18 monitors sensed cardiac signals forcardiac arrhythmic abnormalities including sinus arrhythmia, sinuspause, premature atrial contraction (PAC), premature ventricularcontraction (PVC), irregular rhythm (wandering pacemaker, multifocalatrial tachycardia, atrial fibrillation), asystole or paroxysmaltachycardia) from IMD 14 and, upon abnormality detection, initiatesbrain stimulation via stimulator 16 and lead 24 to suppress an onset ofan epileptic seizure. Note that sensed cardiac events may also includeconduction abnormalities including AV-block (AVB), bundle branch block(BBB) and repolarization abnormalities including T-wave inversion andST-elevation or depression. Lastly, hypertension, hypotension andvaso-vagal syncope (VVS) are common in epilepsy patients and may bemonitored by IMD 14.

Alternatively, coordinator 18 may sense the onset of a seizure andinitiate preventive cardiac stimulation (such as, bradycardia pacing,overdrive pacing, anti-tachycardia pacing (ATP), cardioversion,defibrillation shock, etc.) to suppress cardiac arrhythmia onset. In analternative embodiment, coordinator 18 may initiate diaphragmaticstimulation from IMD 14 via leads not shown in FIG. 15 or,alternatively, vagal stimulation via leads 26 to prevent pulmonaryevents such as obstructive sleep apnea (OSA), central apnea, and/orneurogenic pulmonary edema.

In operation, coordinator 18 receives notice of a sensed arrhythmia orcardiac anomaly via telemetry link 30 from IMD 14 and initiates therapyfrom neuro stimulator or drug pump 16 or, alternatively, from IMD 14 viatelemetry link 30. In an alternative embodiment, coordinator 18 receivesnotice of a sensed epileptic seizure or neuro anomaly via a telemetrylink 30 from neuro stimulator/drug pump 16 and initiates therapy fromIMD 14 or, alternatively, from neuro stimulator or drug pump 16 viatelemetry link 30. In the above descriptions, telemetry link 30 may bean identical link between the coordinator 18 and IMD 14 and neurostimulator/drug pump 16 or, alternatively, the 2 telemetry links may bedifferent as described herein above.

Optionally, coordinator 18 may contain a push button 19 to allow thepatient 10 to communicate some event to the IMDs 14 and 16 such as theonset of an arrhythmia, the feeling of light-headedness, the beginningof a meal, chest pains, to manually activate diagnostic data recording,initiate therapy delivery and the like. Coordinator 18 communicates theclosing of push button 19 to either or both of the 2 IMDs 14 and 16 viatelemetry link 30.

Coordinator 18 may be implemented in any number of mechanicalconfigurations such as wearable configurations such as jewelry, awristwatch or a belt buckle to be worn by the patient or medicalpersonnel or, preferably, an adhesive patch as described above inrelation to FIG. 5 and FIG. 6.

The coordinator 18 may alternatively provide protection for an lowvoltage IMD such as a pacemaker, neuro stimulator, drug pump, ILR from ahigh voltage shock from an ICD by opening the lead connection, the lowvoltage stimulus circuitry and/or the sense amplifier input circuitryjust prior to the delivery of the shock. After delivery of the highvoltage shock, the lead connection, low voltage stimulus circuitryand/or the sense amplifier input circuitry are reconnected and the lowvoltage device returns to normal operation.

FIG. 16 is a diagram 300 of a method of implementing the implantation ofa second IMD, initiating communication between a first and second IMDand initiating system control of the enhanced system consisting of the 2IMDs and coordinator. At step 302, the physician implants a second IMDinto a patient 10 who already has a first IMD. The physician attachescoordinator 18 to the patient 10 at step 304 and initializes thecoordinator. At step 306, the coordinator interrogates the 2 IMDs,receives model and serial number information, and sets up telemetrycommunication between itself and the 2 IMDs. At step 308, thecoordinator initializes enhanced system function utilizing informationfrom the 2 IMDs and a program stored in its memory. At step 310, theenhanced system operation continues per the program instructions andprograms stored in the coordinator memory 36 of FIG. 5.

Alternatively at step 306, the physician could select the telemetrycommunication modes and program the coordinator 18 with the appropriatecommands via programmer 12 to enable the telemetry links 30 to each ofthe IMDs and the flow diagram continuing with steps 308 and 310 asabove.

An alternative embodiment would allow an implanting physician to implanta sensor unit at a remote location in the patient, which would transmitdata to a therapy or diagnostic IMD via coordinator 18. The sensor unitmay include an accelerometer, pressure, O₂sat, pH, flow, dP/dt, acoustic(sound), Doppler ultrasound, impedance plethsymmography, piezo-electric,or the like, sensors located remote from the IMD implant site.Coordinator 18 would facilitate the transfer of data from the sensor tothe IMD to allow improved detection and/or store diagnostic data forlater review by the patient's physician.

A number of embodiments and features of an implantable medical devicecoordinator 18 have been described. The coordinator 18 may take avariety of forms and mechanical configurations in addition to thosedescribed herein. Moreover, the techniques described herein may beimplemented in the inventive device in hardware, software, firmware, orany combination thereof. If implemented in software, the invention maybe directed to a computer readable medium comprising program code, thatwhen executed, performs one or more of the techniques described herein.For example, the computer readable medium may comprise a random accessmemory (RAM), SDRAM, FLASH, or possibly a removable memory card asoutlined herein. In any case, the memory stores the computer readableinstructions that, when executed cause coordinator 18 to carry out thetechniques described herein. These and other embodiments are within thescope of the following claims.

1. A system comprising: a first implanted medial device; a secondimplanted medial device; and a coordinator that receives data via afirst communication signal from the first medial device, produces afunction command, generates a second communication signal and sends thefunction command via the second communication signal to the secondmedical device.
 2. The first implantable medical device of claim 1selected from the group consisting of a pacemaker, a defibrillator, acardioverter/defibrillator, a drug pump, a neuro stimulator, an ILR anda remote sensor.
 3. The second implantable medical device of claim 1selected from the group consisting of a pacemaker, a defibrillator, acardioverter/defibrillator, a drug pump, a neuro stimulator, an ILR anda remote sensor.
 4. The function command of claim 1 coordinates therapybetween the first and second implantable medical devices.
 5. The therapyof claim 4 selected from the group consisting of pacing,cardioversion/defibrillation, neuro stimulation and drug delivery. 6.The function command of claim 1 coordinating sensing and monitoringbetween the first and second implantable medical devices.
 7. Thefunction command of claim 1 providing pain suppression to the patientfrom a first implantable medical device prior to or during therapy fromthe second implantable medical device.
 8. The function command of claim1 providing reduced defibrillation or pacing threshold of the patientfrom a first implantable medical device prior to or during therapy fromthe second implantable medical device.
 9. The function command of claim1 providing remote sensor data from the first implantable medical deviceto the second medical device.
 10. The function command of claim 1providing device protection to the first implantable medical deviceduring therapy delivery from the second implantable medical device. 11.The remote sensor data of claim 9 selected from the group consisting ofacceleration, pressure, O₂sat, pH, flow, dP/dt, acoustic (sound),Doppler ultrasound, impedance plethsymmography and piezo-electric. 12.The coordinator of claim 1 mounted externally to the patient.
 13. Thecoordinator of claim 12 selected from the group consisting of a wristwatch, a belt, a necklace, a piece of jewelry, an adhesive patch, apager, a key fob, an identification card, a laptop computer, aninterrogator and a hand-held computer.
 14. The first and secondcommunication signals from the coordinator of claim 1 consisting of atrancutaneous telemetry transmission.
 15. The first and secondcommunication signals of claim 14 selected from the group consisting ofRF, electromagnetic, ionic and acoustic.
 16. The coordinator of claim 1communicating between 2 IMDs selected from the group consisting of apacemaker and ICD, a pacemaker and drug pump, an ICD and drug pump, apacemaker and neuro stimulator, an ILR and pacemaker, an ILR and ICD, anILR and neuro stimulator, an ILR and drug pump and an ICD and neurostimulator.
 17. The neuro stimulator of claim 16 providing therapy tothe patient's vagus nerve or brain.
 18. The pacing therapy of claim 5selected from the group consisting of ATP pacing, overdrive pacing andbradycardia pacing.
 19. The reduced ICD pain delivery of claim 7selected from the group consisting of a neuro stimulator and drug pump.20. The reduced defibrillation shock threshold of claim 8 reduced bytherapy delivered from an IMD selected from the group consisting of aneuro stimulator, a drug pump and a pacemaker.
 21. The coordinatedsensing of physiologic data of claim 6 selected from the groupconsisting of cardiac signals, respiration signals and EEG signals. 22.The neuro stimulator or drug pump of claim 5 providing therapy for adisease selected from the group consisting of Parkinson's and epilepsy.23. The communication system of claim 1 with telemetry setup selectedfrom the group consisting of automatic setup, physician programmed andimplant detect and automatic setup.
 24. The coordinator of claim 1including a digital signal processor (DSP) circuit comprising: means forreceiving a data signal from a first IMD; means for generating a controlcommand; and means for modulating a second signal with said functioncommand and transmitting said second signal to a second IMD.
 25. Thecoordinator of claim 24 further comprising: an antenna system; areceiver in operable communications with the antenna for receiving andamplifying of said data signal; and a transmitter for transmitting afunction command to said one of IMDs.
 26. The coordinator of claim 24further comprising: a patient activated push button for providing manualinput by the patient selected from the group consisting of arrhythmiaonset, the feeling of light-headedness, the beginning of a meal, chestpains, to manually activate diagnostic data recording and initiatetherapy delivery.
 27. The monitoring therapy of claim 6 selected fromthe group consisting of EEG, cardiac, obstructive sleep apnea (OSA),central apnea and neurogenic pulmonary edema.
 28. A method ofcoordinating the function of 2 IMDs implanted in a patient, comprising:receiving a communication signal from a first IMD; decoding the datafrom said communication signal; utilizing said decoded data to generatea function command for said second IMD; modulating a secondcommunication signal with said data; transmitting said secondcommunication signal to said second IMD; receiving said secondcommunication signal by said second IMD; and causing the second IMD tooperate in a specific function/method.